[SOLVED] Do I need a second Rad for an RTX 30 build?

[Ronnie30]

Hi All,

I'm currently running a custom water cooling loop with a 360 rad, that is only cooling my CPU (i7-6700k). My current GPU (GTX 1080) is air cooled. I will be getting an RTX card (probably 3080, maybe 3090 if the stars align and budgets can be met), and when it finally releases, I may upgrade to an 11th gen Rocket Lake CPU as well (yes, Ryzen is kicking ass in multithreaded applications right now, but I'm potentially spending a lot on a new 3440x1440 monitor and an RTX 3090, so I want to really eke out every frame I can, in games...but we'll see how Ryzen stacks up when Rocket Lake comes out and I'll decide then).

Initially my plan was to add only the GPU to the loop, but with the expected power draw of the RTX 30 series, will I need an additional radiator? I can fit another 360 in, though I may only use a 240, so that I have more air coming in than out (positive pressure). If I remove all other case fans, so that I only have 3 static fans on the front 360 rad, and 2-3 static fans on the top mounted rad, will this be suitable, or will the incoming air, warmed up by the front rad, nullify any benefit I may get from a second, top mounted rad?

Edit: Looking at an EVGA Hydro Cooler GPU; not a founders edition. Will be doing some light CPU/GPU overclocking but nothing insane.

 

[Ronnie30]

I went through the radiator excel sheet that I found pinned on these forums, to calculate rad size needed. It suggests that a 360mm should be sufficient at the lowest flow rate (can't figure out what my pump flow rate is so using the worst case scenario). Still curious if I'm going to see any benefit from adding an extra 240mm rad to the loop though, or if it's just going to pull through hot air and not be worth it.